purchasing a gun. its 30 second super bowl ad airing in the d.c. market features claim of nra president wayne lapierre testifying before congress in 1999. >> we think it's reasonable to have manner to background checks for of sale at every gun show, no loopholes -- for every sale at every gun show, no loopholes. >> reporter: he says background checks for all gun originals as recommended by president obama -- owners as recommended by president obama would only lead to a gun registry. >> the criminals aren't going to comply with it. they could care less. you've already seen you won't computerize the mental health records. we ought to quit calling it right now a universal check. the real title ought to be the check on law abiding people all over this country. >> how do we know? let's start the effort and then we'll see. >> reporter: mayors against illegal guns is calling for not only background checks but a ban on assault weapons. one area where mayor gray does agree with lapierre. >> we've historically had police officers in our schools and i see something nothing wrong with that. i think it'